Method of and apparatus for finishing cylindrical bearing surfaces



March A1 1927. l 1,619,479

G. R. MAUPIN METHOD OF AND APPARATUS FOR FINISHING CYLINDRICAL BEARING SURFACES Filed Feb. l, 1926 2 Sheets-Sheet ly March 1 1927.

G. R. MAUPIN Filed Feb. l, 1926 2y Sheets-Sheet 2 Patented Mar. l., 1927.

e UNITED STATES 1,619,479 PATENT orrlca.

GRAVES R. MAUPIN, MOBERLY, MISSOURI, ASSIGNOR T THE J'. FAESSLER MANU- FACTUBING COMPANY, CHRISTINIA FAESSLER, LOUIS E. MOBERLY, MISSOURI.

A COPABTNERSHIP COMPOSED OF JOHN W. FAESSLER, FAESSLER, AND GRAVES R. MAUPIN, .ALL OF METHOD 0F AND AIPILARATUS FOR, FINISHING CYLINDRICAL BEARING SUBFACES.

Application filed February My invention relates vto improvements in method of and apparatus for finishing cylindrical bearing surfaces, and has Vfor its primary object the method of finishing a cylindrical bearing surface whereby the bearing surface is given an extremely smooth finish and also toughened during the finishing operation.

A further object is the finishing of a cylindrical bearing surface by applying a rolling pressure thereto thus compressing the surface and toughening the same.

A further object is to construct an apparatus for nishing cylindrical bearing surfaces in which a plurality of expanding rollers are employed which give the surface Vof the bearing treated thereby a smooth mirror-like finish.

A still further object is to construct, an

apparatus which will not only finish cylindrical bearing surfaces butwhich can also be used for tightening bushings throughout their length in all types ,of cylinders and without the use of hydraulic presses or heating and shrinking the cylinder on to the bushing as is at the present time done. One of the important features resulting from my method and apparatus is the rolling of a true smooth wearing surface and by so doing compress and toughen this wearing surface so that all grinding or honing of the surface is eliminated. Another feature is that a cylinder or a cylindrical bearing surface so "finished does not have to be worked in as is necessary where cylinders have been ground or honed.

A still further advantage of my device is that a bearing surface treated by my apparat-us and method is free from all particles of abrasive, which is not the case where cylinders are ground or honed, for the reason that small particles of abrasive areV forced into the. pores of the metal and there is always a possibility of the bearings becoming scored from such particles.

y In the drawings: i

Fig. 1 is a sectional view of afcylinder showing my device in position in the act of rolling in a bushin Fig. 2 is a longitudinal section of a cylinder showing a modified form of my device therein in which the bearing surface and the cylinder itself is being treated;

1, 1928. Serial No. 85,149.

Fig. 3 is an end view of Fig. 1 looking in the direction of the arrow 3;

Fig. 4 is a longitudinal section of the apparatus illustrated in Fig. 1;

Fig. 5 is an enlarged face view of the sliding collar employed;

Fig. 6 is a lon itudinal section of the apparatus employe in Fig. 2;

Fig. 7 is an enlarged view of one of the expander rollers;

Fig. 8 is a fragmental diagrammatic section showing the molecular structure of a piece of metal before being treated by my method; and

Fig. 9 is a similar view showing the metal after being treated.

In the construction of my device, 10 represents a cylinder which has been bored out and in which a bushing 11 has been inserted. 4This bushing is preferably cast iron, brass or bronze as found necessarv as my device can be used in engine cylinders, pump cylinders, or in fact in any place where a cylindrical bearing surface is required.

My apparatus as illustrated in Fig. 1 is constructed in the following manner 12 represents a cage which has aI plurality f.'

of slots or openings 13 formed in its periphery. These openings are preferably at an angle to the longitudinal axis of the cage and each opening has located therein a roller 14. These rollers when in position will have their longitudinal axis at an angle to the longitudinal' axis of the cage. The cage is provided with a central bore 15 in which is located an expanding head 16. This expanding head contacts with'the face of the rollers 14. The expanding headis tapered so that as it is fed forward, it will force the rollers outward and cause them to bear against the cylindrical surface in such a manner that the rollers will bear throughout their length against the cylindrical surface and also against the expanding head thereby preventing the rolling of any ridges in the cylindrical surface. The expanding head 16 is provided with a central bore 17 which has a key-way 18 formed therein in which the key 19 is located. The key 19 is also seated in the reduced portion 20 of the mandrel 21. By thismeans the head 16 and mandrel 21 rotate simultaneously. The head 16 is held on the mandrel by means of the nut 22.

sleevel 23 in which a thrust bearing 24 is seated. The mandrel 21 .is rovided with a key-way 25 and screw threa s 26. Mounted on the mandrel 21 is a sliding collar 27 which is provided with a key 28. This key is seated in the key-way 25 and in this manner the collar 27 is held against any rotation on the mandrel but is free to slide longitudinally. Mounted on the screw threaded portion of the mandrel is a collar 29 whichl is screw threaded so that it can move longitudinally by being turned. The collar 29 is provided with a recess in which is mounted a block 30. This block is provided with screw threads as illustrated in Fig. 4 and A1s designed to be pressed against the mandrel by means of a set screw 31. In this manner the collar 29 can be locked on the mandrel without disturbing or mutilating the screw threads in any way. The purpose of the collars 27 and 29 is to form a depth gauge for the expanding hea and prevent it -from pushing the rollers outward beyond a predetermined distance.

The mandrel 21 is also provided with openings 32 and 33 arranged at right angles to each other through which a bar can be inserted for rotating the mandrel and w1th a square ,end 34 by means of which the mandrel can be rotated either by a wrench or handle or by means of a power-driven device.

In Fig. 6 I have shown a slightly modified form of apparatus in which the cage is provided with a sleeve 36 formed integral therewith. This sleeve is screw threaded' as at 37 and has placed thereover a screw threaded sleeve 38 and a lock nutl 39. --In this construction the mandrel' 40 is not provided with screw threads b ut has a collar 41 formed integral therewith and adjacent the end opposite the expander head 42. The expander head 42 is held on the mandrel by means of the key 43 and nut 44. Adjacent. the collar 41 is a s uare portion 45 by means of which the man rel can be rotated, and interposed between the collar 41 and sleeve 38 is a thrust washer 46. This washer is loosely mounted on the mandrel and is designed to receive the thrust from the collar 41 and eliminate twisting action on the sleeve 38 'as much as possible.` The locknut 39 is for the purposeof preventing the `accidental movement on the sleeve after it has once been adjusted. The sleeve 38 and collars 41 and 46act as a de thgauge for preventing the rollers 47, whlch are of the same construcion as the rollersy "14, from expanding too The operation of my device is as follows:

I will first `explain the method of finishing the interior of a cylinder. .The cylinder after coming from the foundry 1s first placed -in a boring mill and bored out to approxithe axis of the cage, the mandrel will feed I forward, expanding the rollers and causing them to bind tightly against the interior of the cylinder. l Continued rotation of the mandrel causes the rollers to rotate and in so doing causes the entire apparatus to move longitudinally through the cylinder, compressing the metal and ironing out all of the tool marks. After the apparatus has been passed through the cylinder, itis withdrawn, the gauge moved back 'a slight distance, and the operation repeated until the proper size of bore has been reached. It is to be understood, of course, that the bore o fthe cylinder is approximately the finished size because'by my method I do not remove any material from the bearing surface but only compressor condense the surface. During this operation of rolling, it is, of course, necessary that the interior surface of .the cylinder be lubricated, and I have foundy that during the operation a certain amount 0f lubricant is 'forced linto the pores of the metal and retained thereby. This also .makes it easier when breaking ma new` cylinder because I vhave found that a cylinder treated by my method and afterward washed out and dried so that no trace of lubricant remains therein, upon bein heated oozed lubricant into the fg cylinder romv the f cylinder walls, thus assisting greatly in the breaking in operation and 'eliminating the excessive use of oil during such operation.

en my device' is used on cylinders which have been bushed, it is not necessary to force the bushing in by means of a hydraulic press, to heat the same so that they will ex and sufliclently to permit the insertion o the bushing and then shrink them on the bushing as the cylinder is bored out to allow or in cases of large cylinders' for the insertion of the bushing and the exocomotives it` the bushing made so that and after boring out the cylinders heat them and shrink them on to the bushing. This makes anexpensive operation and if the bushing is too large, there is always a possible chance of cracking the cylinder.

I have also discovered that by the use of my apparatus a true bore can be obtained. This, it is virtually impossible to obtain by means of a grinding machine on account of the Wear of the abrasive so that one end of the cylinder will always be a trifie smaller than the other and therefore a perfect bearing or fit can not be obtained. This is especially true of engine and pump cylinders Where thepiston travels backward and forward. A cylinder' with a taper as just described is extremely hard on the piston rings because they are constantly being compressed and expanded, which crystallizes them and causes them to Wear out much more rapidly than if a true cylindrical sur face were obtained.

While I have described my device as being used for engine and pump cylinders, it can be used for any kind of cylindrical bearings and a bearing so treat-ed does not have to be scraped and fitted. This makes my device especially adapted for locomotive main and side connecting rod bushings, and all sorts of cylindrical bearing bushings, as Well as cylindrical bearings and cylinders of all kinds without bushings as the bearing surface of the latter can be readily treated and condensed and `toughened by my process. My device can also be used to vadvantage in repairing scored automobile cylinders in which grooves have been cut deep enough to require filling in by metal as the filling can be packed in much more tightly and finished with less labor and time than is now required.

My device may be made of any size and employ any number of rollers from three on up, depending on the size of the apparatus and the class of work for which it is intended. In Fig. 8 I have shown a fragmental section of a portion of a cylinder before the same has been treated, as it would appear when enlarged many diameters and showing the molecular struct-ure. In this it will be plainly seen that thev molecules are evenly distributed throughout the piece Whereas in Fig. 9 the molecules along the treated surface are very much condensed. This condensing not only makes the surface smooth and eliminates pores but also has a tendency to toughen the metal thereby increasing its life and preventing it from l wearing away as rapidly as if the natural surface was exposed to wear.

It is to be understood, of course, that the rollers 14 and the expanding head 16 ,are both made of hardened tool steel. It is further to be understood that in rolling small cylindrical bearing surfaces the expanding head 16 is eliminated and the forward end of the mandrel 21 is tapered, this tapered portion acting in the same manner as the expanding head, that is as it is fed into the cage, it will force the rollers outward causing them to engage against the surface to be treated.

It will be obvious from the foregoing description ofthe operation of my device that the same will feed itself automatically through the bushing to be finished and is not dependent on any extraneous pressure exerted along its longitudinal axis to accomplish this movement.

It will also be further noted that with my device it is not necessary to heat the bushing to be finished but that my method is directed vsolely to a cold finished process.

Having fully described vmy invention, WhatI claim is l. The method of finishing a cylindrical bearing surface which consists in applying to said'surface a sufficient pressure by a rolling contact to compress and smooth the wearing surface of said bearing, and cansinor said rolling contact to move said pressure ongitudinally of the surface.

2. The method of finishing a cylindrical bearing surface which consists in applying to said surface a gradually increasing rolling pressure, and simultaneously moving said pressure longitudinally along said Surface without the use of extraneous feeding means whereby the texture of said bearing adjacent the surface is rendered more compact and dense and the surface toughened.

3. The method of finishing a cylindricaly bearing surface which consists in applying pressure to said surface at equally spaced apart circumferential points, and then moving said points of pressure circumferentially and longitudinally automatically throughout the length of the surface.

4. An apparatus of the class described comprising a cage, expanding rollers mounted in said cage said rollers having their longitudinal axis at an angle to the longitudinal axis of the cage and adapted to be projected beyond the periphery thereof, an expanding head mounted in said cage and contacting with said rollers, a mandrel secured to said expanding head, means for securing said mandrel andA head together against independent rotation, adjustable means for limiting the forward movement -of said expanding head for regulating the projection of said rollers, and means on one end of said mandrel and adapted to receive a means for rotating said mandrel.

5. An apparatus of the class described comprising a cage, expanding rollers mounted in said cage and having their longitudinal axis at an angle to the longitudinal axis of said cage, a tapered expanding head mounted in said cage and contacting with said rollers, a mandrel secured to'said expanding head and projecting rearwardly therefrom and from said cage, said mandrel and expanding' head being secured together against independent. rotation, adjustable means mounted on said mandrel and adapted to contact with the cage for limiting the forward movement of the expander head within said cage, the rear end of the`man drel arranged to receive a means wherebyl the mandrel can be rotated.

6. An apparatus of the class described comprising a. cage, a sleeve integral ywith said cage, rollers located in said cage and adapted to have their periphery projected beyond the periphery of the cage, the longitudinal axis of said rollers being at an angle.

to the longitudinal axis of the cage whereby said cage is automatically moved forward when rotated, a mandrel movable centrally through said sleeve and projecting into said cage, a tapered expanding head mounted on one end of said mandrel1 means for securing said mandrel and expanding head together so that the same Will rotate simultaneously, a collar formed integral with said mandrel adjacent its rear end, a" second sleeve adjustably mounted on said first mentioned sleeve v rendered more compact and Adense and the surface given a smooth finish. j

8. The method of cold finishing a cylindrical bearing surface which consists in subjecting said surface to an outwardly directed circumferentially and an automatically longitudinal inging rolling pressure of sufficient intensity to` render lsaid surface` smooth and the texture of said bearing adjacent said surface more dense and compact.

9. The method of finishing a cylindrical bearing surface which consists in applying a'lubricant to said surface, subjecting said surface to a longitudinally traveling outwardly directed cireumferentially moving pressure at circumferentially spaced apart points throughout its length, and repeating the application of said pressure until the texture of the bearing adjacent said surface has been rendered more dense and a smooth bearing surface of a predetermined diameter obtained. 4 v

10. The method of finishing a cylindrical bearing surface which consists in applying to said surface at circumferentially space apart points an outwardly directed. pressure sufficient to compress and smooth the wearing surface of said bearing, moving said pressure longitudinally of the bearing while it isL being applied and simultaneously therewith enlarging theoutside diameter of said bearing.

11. The method of finishing the inside of bushings and similar cylindrical bearings, which consists in subjecting the surface to be finished to a longitudinally extending radially directed outward rolling pressure, moving said pressure circumferentially and longitudinally of said surface and simultaneously therewith increasing the outside diameter of said bushing.

12. The method of finishing the inside surface of cylindrical bushings, which consists in placing said bushing in a cylindrical bore of slightly greater diameter than the outside of said bushing, subjecting the interior of the bushing to a longitudinally extending radially directed outward rolling pressure moving longitudinally and circumferentially through said bushing whereby v the interior surface of said bushin is smoothed and condensed and said bus inosimultaneously expanded and tightly seated within the cylindrical bore.

13. The method of finishing and toughening the internal wearing surface of cylindrical' bearings, which consists in subjecting said surface progressively throughout its length to a slow longitudinally moving outwardly directed rolling pressure simultaneously exerted at circumferentially spaced apart points, and repeating said operation until the desired internal diameter is obtained whereby a smooth condensed wearing surface is obtained.

In testimony whereof I have affixed my signature.

GRAVES R. MAUPIN. 

